(a) Technical Field
The present invention relates to a cell voltage measuring connector for a fuel cell stack, and more particularly, to a cell voltage measuring connector for a fuel cell stack in which a locking boss of a connection position assurance component (CPA) is inserted into a locking recess of a terminal of a separating plate to remain locked to prevent a connector from detaching from the separating plate of a stack due to an external impact such as a vibration or a collision of a vehicle.
(b) Background Art
In general, a fuel cell, which is a high efficiency clean energy source, has been increasingly used in various areas, and particularly, a Polymer Electrolyte Membrane Fuel Cell (PEMFC) among various types of fuel cells operates at a low temperature relative to other fuel cells, and has rapid start and response characteristics, therefore is being actively developed as a mobile electric power for a vehicle.
A stack of a PEMFC is formed through laminating of unit cells as required, each of which unit cells includes a Membrane Electrode Assembly (MEA) formed of a fuel electrode, an air electrode, and a polyelectrolyte film between the fuel electrode and the air electrode, and a separating plate which is referred to as a bipolar plate, and is made of a metal material.
Electric potential generated in a cell corresponds to about 0.6 V to 1.3 V and a plurality of cells are laminated in series to produce an electric power necessary for driving the vehicle. A current collector and a compression plate are disposed at opposite sides of the laminated separating plates, respectively, and a tie bar is installed to pass through the current collector and the compression plate, which maintains the stack configured as above in an assembly state.
Meanwhile, to check performance and failure of the stack in a vehicle, the separating plate of each cell is connected to a control circuit (e.g., a circuit that includes an electronic control unit for operating a fuel cell system in a measuring device and a vehicle) via a connector and a conducting wire, and a voltage of each cell is measured. Terminals inserted into the connector are protruded at predetermined locations on a side surface of the separating plate, and thus when a stack assembly is completed, the terminals form a terminal line on a side surface of the stack, and the connector is mounted to the terminal line.
However, since the connector according to the related art is formed integrally with a length that corresponds to the whole stack, and is manufactured to have the terminals of all the separating plates inserted into the connector, when an alignment of the separating plates is not substantially accurate when the stack is manufactured, it may be impossible to assemble the connector in the stack due to a misalignment of the terminals of the separating plates. Thus, when the connector is mounted, the terminals of the separating plates may be deflected (e.g., deformed) or damaged. Further, since the connector is used in a vehicle and is influenced by vibrations or an impact due to driving of the vehicle, a voltage value may not be accurately measured and the connector may be separated from the stack when the contact states of the connector and the terminals of the separating terminals are not substantially firm. For example, the measured voltage values may fluctuate.
A cell voltage measuring connector for a fuel cell stack of a vehicle of the related art, includes a housing that has a terminal insertion slit into which a terminal of one of a plurality of terminal rows formed at sides of separating plates of a stack on a rear surface thereof is inserted, a connecting terminal insertion aperture that communicates with the terminal insertion slit and is formed on a front surface thereof; a base frame that has an aperture that corresponds to the connecting terminal insertion aperture; a terminal positioning assurance (TPA) terminal formed in the base frame and inserted into the TPA terminal insertion aperture; a TPA that has a side fixing end formed on a side surface of the base frame and fixedly attached to a side surface of the housing; a terminal connecting portion inserted into the connecting terminal insertion aperture of the housing through the aperture and connected to the terminal of the separating plate; and a wire chucking portion wired to the terminal connecting portion and connected to an end of a wire connected to a control circuit.
However, the cell voltage measuring connector for a fuel cell stack in the related art may easily separate from the separating plates due to vibrations and an impact of the vehicle, thus deteriorating a reliability of the product. Further, when the separating plates are thin films having a thickness of about 0.1 mm or less, a contact force of the terminal connecting portion becomes vulnerable and the connecting terminals may easily separate from the terminals of the separating plates.